INTERSTATE FISHERIES MANAGEMENT PROGRAM IMPLEMENTATION FOR NORTH CAROLINA By Kevin Brown Completion Report for NOAA Award No. NA08NMF474076 Study II DOCUMENTATION AND REDUCTION OF BYCATCH IN NORTH CAROLINA FISHERIES JOB 1: Compare catch rates of shrimp and bycatch of other species in standard (control) and modified (experimental) otter trawls in the Neuse River and Pamlico Sound, North Carolina. February 2010 ABSTRACT The purpose of this project was to identify potential gear modifications that can be implemented by the commercial shrimp trawl fishery to reduce bycatch in the fishery. Gear comparisons were made using five modified shrimp trawl tail bags in the Neuse River and Pamlico Sound, North Carolina from 1 July 2008 to 30 June 2009 to determine methods of reducing bycatch while maintaining shrimp harvest. Five experimental otter trawls were tested against a standard (1 ½” stretch mesh, hung on the diamond) tail bag. The experimental nets had 1 ¾ inch stretch mesh (hung on the diamond, 1 ¾ inch stretch mesh (hung on the square), 2 inch stretch mesh (hung on the square) mesh tail bags. Otter trawls equipped with the Jones-Davis BRD (bycatch reduction device) and a skylight panel were also tested. The shrimp catch of all five tests nets was not significantly different from the standard net; however with the exception of the 1 ¾ inch stretch mesh (hung on the diamond) all the test nets caught significantly less bycatch. The results of this study offer insights for fishery managers developing Fishery Management Plans and may assist in gear regulations in North Carolina’s commercial shrimp trawl fishery. Recommendations include continued experimentation of gear modifications in inshore and nearshore areas of North Carolina, potentially implementing gear regulations based on experimental designs, and continuing and improving collaboration and outreach to the industry to develop and implement gear to reduce bycatch in the shrimp trawl fishery of North Carolina. ii TABLE OF CONTENTS ABSTRACT .................................................................................................................................. ii TABLE OF CONTENTS ............................................................................................................. iii LIST OF FIGURES...................................................................................................................... iv LIST OF TABLES ......................................................................................................................... v INTRODUCTION .......................................................................................................................... 1 METHODS..................................................................................................................................... 2 GEAR PARAMETERS.............................................................................................................. 3 RESULTS ...................................................................................................................................... 4 SPECIES COMPOSITION ....................................................................................................... 5 Length Frequencies ................................................................................................................ 16 Statistical Analysis .................................................................................................................. 19 Sea Bird and Protected Species Bycatch ........................................................................... 20 DISCUSSION .............................................................................................................................. 20 RECOMMENDATIONS ............................................................................................................. 21 LITERATURE CITED................................................................................................................. 23 iii LIST OF FIGURES Figure 1. Study areas for shrimp trawl gear testing in the Neuse River and Pamlico Sound, North Carolina from 1 July 2008 through 30 June 2009. ............................................................ 4 Figure 2. Length frequency of shrimp observed during gear tests of the 1 ¾” stretch mesh, hung on the diamond in the Neuse River and Pamlico Sound, North Carolina 1 July 2008 to 30 June 2009. .............................................................................................................................. 17 Figure 3. Length frequency of shrimp observed during gear tests of the 1 ¾” stretch mesh, hung on the square in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. .................................................................................................................................. 17 Figure 4. Length frequency of shrimp observed during gear tests of the 2” stretch mesh, hung on the square in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ........................................................................................................................................ 18 Figure 5. Length frequency of shrimp observed during gear tests of the Jones Davis BRD in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. .......... 18 Figure 6. Length frequency of shrimp observed during gear tests of the skylight panel in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ................. 19 iv LIST OF TABLES Table 1. Characteristics of otter trawls, including the standard and experimental configurations tested in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ................................................................................................................................. 3 Table 2. Relative biomass (kg) and number of individuals observed in the standard net during gear tests of the 1 ¾” stretch mesh, hung on the diamond in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ........................................................ 6 Table 3. Relative biomass (kg) and number of individuals observed in the experimental net (1 ¾” stretch mesh, hung on the diamond) in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ............................................................................. 7 Table 4. Relative biomass (kg) and number of individuals observed in the standard net during gear tests of the 1 ¾” stretch mesh, hung on the square in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ........................................................ 9 Table 5. Relative biomass (kg) and number of individuals observed in the experimental net (1 ¾” stretch mesh, hung on the square) in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ........................................................................... 10 Table 6. Relative biomass (kg) and number of individuals observed in the standard net during gear tests of the 2” stretch mesh, hung on the square in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ...................................................... 11 Table 7. Relative biomass (kg) and number of individuals observed in the experimental net (2” stretch mesh, hung on the square) in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ........................................................................... 12 Table 8. Relative biomass (kg) and number of individuals observed in the standard net during gear tests of the Jones Davis BRD in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ........................................................................... 13 Table 9. Relative biomass (kg) and number of individuals observed in the experimental net (Jones Davis BRD) in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ................................................................................................................. 14 Table 10. Relative biomass (kg) and number of individuals observed in the standard net during gear tests of the skylight panel in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ............................................................................................. 15 Table 11. Relative biomass (kg) and number of individuals observed in the experimental net (skylight panel) in the Neuse River and Pamlico Sound, North Carolina, 1 July 2008 to 30 June 2009. ...................................................................................................................... 16 v INTRODUCTION North Carolina’s shrimp fishery targets three species of shrimp; brown (Farfantepenaeus aztecus), pink (Litopenaeus setiferus), and white (F. duorarum). All three species are considered annual crops implying that environmental conditions rather than fishery pressure regulates population size. All three commercially important shrimp in North Carolina are considered viable (NCDMF 2006; NCDMF 2008). Shrimp harvest in the Neuse River and Pamlico Sound accounted for 67% of the state’s shrimp harvest in 2008. Low cost imported shrimp, regulatory changes, and increased fuel prices have strained the industry and are likely contributing factors to the gradual decline